<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" type="text/css" href="test.css">
</head>
<body>

<body class="HolyGrail">
<header>...</header>
<div class="HolyGrail-body">
    <main class="HolyGrail-content">...</main>
    <nav class="HolyGrail-nav">...</nav>
    <aside class="HolyGrail-ads">...</aside>
</div>
<footer>...</footer>
</body>

</body>
</html>